According to ESPN:
Marell Evans, LB, is going to transfer and DLineman Vince Helmuth is checking out his options as well
Helmuth was 4 deep at DT. Rivals rated him a 3 Star, #9 FB in '07. UM is the only offer listed perhaps because he committed on January 29,
2006. His future was sealed mostly likely when 5 Star DL William Campbell signed with UM last Feb.
Evans was a #2 LB on the depth chart. Rivals rated him a 2 star Unranked LB. He has 2 offers listed UM and Temple.
When Rodriquez arrived his offense and/or style of coaching drove off QB Mallet and OG Boren who starts for OSU. McGuffie transferred back home to TX in less than a year be it family circumstances or the coach. Aside from them most of the transfers seem to marginal guys like Helmuth, Evan, and Weems.
I suspect Rodriquez and company are driving off the marginals to create slots for more talented prospects. This is addition by subtraction.
Michigan got a big boost for their secondary as J.T. Turner 6-2 185 was cleared academically to play this season. He's a backup up corner on UM's 2 Deep.